Cognard Type V dural arteriovenous fistulas (dAVFs) are a unique type of cranial vascular malformation characterized by congestion of the perimedullary venous system that may lead to devastating spinal cord pathology if left untreated. The authors present the first known case of a pediatric patient diagnosed with a Type V dAVF. A 14-year-old girl presented with a 3-week history of slowly progressive unilateral leg weakness that quickly progressed to bilateral leg paralysis, sphincter dysfunction, and complete sensory loss the day of her presentation. MRI revealed an extensive T2 signal change in the cervical spine and tortuous perimedullary veins along the entire length of the cord. An emergency cranial angiogram showed a Type V dAVF fed by the posterior meningeal artery with drainage into the perimedullary veins of the cervical spine. The fistula was not amenable to embolization because vascular access was difficult; therefore, the patient underwent urgent suboccipital craniotomy and ligation of the arterialized venous drainage from the fistula. The patient’s clinical course immediately reversed; she had a complete recovery over the course of a year, and she remains asymptomatic at the 2-year follow-up. This report adds to a growing body of evidence that describes the diverse and unpredictable nature of Type V dAVFs and highlights the need to obtain a cranial angiogram in pediatric patients with unexplained myelopathy and cervical cord T2 signal change on MRI.
Walter J. Jermakowicz, Alexander G. Weil, Artyom Vlasenko, Sanjiv Bhatia, and Toba N. Niazi
Toba Niazi, Alfredo Quinoñes-Hinojosa, and Meic H. Schmidt
✓ Halo orthoses are commonly used in the management of a variety of cervical spinal pathological conditions. Although placement of the cranial pins was initially believed to be safe with minimal complications, minor complications related to the cranial pins have the potential to create a setting for formation of cerebral abscesses. The risk of death due to cerebral abscesses has declined in the modern antibiotic era, but cerebral abscesses are associated with long-standing neurological morbidity that should not be considered negligible. Prevention by careful pin placement and hygiene and appropriate early management are crucial to prevent more serious complications. The authors report the case of a patient treated with a halo orthosis after incurring cervical spinal trauma who developed a cerebral abscess as a complication related to the cranial pins of the halo fixation device. They review the literature in an attempt to formulate a standardized treatment algorithm to prevent this disease process and to treat an abscess if it should form.
Alexander G. Weil, Andrew L. Middleton, Toba N. Niazi, John Ragheb, and Sanjiv Bhatia
Operations on tumors of the posteromedial temporal (PMT) region, that is, on those arising from the posterior parahippocampal, fusiform, and lingual gyri, are challenging to perform because of the deep-seated location of these tumors between critical cisternal neurovascular structures and the adjacent temporal and occipital cortexes. Traditional surgical approaches require temporal or occipital transgression, retraction, or venous sacrifice. These approaches may result in unintended complications that should be avoided. To avoid these complications, the supracerebellar-transtentorial (SCTT) approach to this region has been used as an effective alternative treatment in adult patients. The SCTT approach uses a sitting position that offers a direct route to the posterior fusiform and lingual gyri of the temporal lobe. The authors report the feasibility, safety, and efficacy of this approach, using a modified lateral park-bench position in a small cohort of pediatric patients.
The authors carried out a retrospective case review of 5 consecutive patients undergoing a paramedian SCTT approach between 2009 and 2014 at the authors' institution.
The SCTT approach in the park-bench position was used in 3 boys and 2 girls with a mean age of 7.8 years (range 13 months to 16 years). All patients presented with a seizure disorder related to a tumor in a PMT region involving the parahippocampal and fusiform gyri of the left (n = 3) or right (n = 2) temporal lobe. No procedure-related complications were observed. Gross-total resection and control of seizures were achieved in all cases. Tumor classes and types included 1 Grade II astrocytoma, 1 pleomorphic xanthoastrocytoma, 1 ganglioglioma, and 2 glioneural tumors. None of the tumors had recurred by the mean follow-up of 22 months (range 1–48 months). Outcomes of epileptic seizures were excellent, with seizure symptoms in all 5 patients scoring in Engel Class IA.
The SCTT approach represents a viable option when resecting tumors in this region, providing a reasonable working corridor and low morbidity. The authors' experience in a cohort of pediatric patients demonstrates that complete resection of the lesions in this location is feasible and is safe when involving an approach that involves using a park-bench lateral positioning.
Manish Kuchakulla, Ashish H. Shah, Valerie Armstrong, Sarah Jernigan, Sanjiv Bhatia, and Toba N. Niazi
Carotid body tumors (CBTs), extraadrenal paragangliomas, are extremely rare neoplasms in children that often require multimodal surgical treatment, including preoperative anesthesia workup, embolization, and resection. With only a few cases reported in the pediatric literature, treatment paradigms and surgical morbidity are loosely defined, especially when carotid artery infiltration is noted. Here, the authors report two cases of pediatric CBT and provide the results of a systematic review of the literature.
The study was divided into two sections. First, the authors conducted a retrospective review of our series of pediatric CBT patients and screened for patients with evidence of a CBT over the last 10 years (2007–2017) at a single tertiary referral pediatric hospital. Second, they conducted a systematic review, according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, of all reported cases of pediatric CBTs to determine the characteristics (tumor size, vascularity, symptomatology), treatment paradigms, and complications.
In the systematic review (n = 21 patients [includes 19 cases found in the literature and 2 from the authors’ series]), the mean age at diagnosis was 11.8 years. The most common presenting symptoms were palpable neck mass (62%), cranial nerve palsies (33%), cough or dysphagia (14%), and neck pain (19%). Metastasis occurred only in 5% of patients, and 19% of cases were recurrent lesions. Only 10% of patients presented with elevated catecholamines and associated sympathetic involvement. Preoperative embolization was utilized in 24% of patients (external carotid artery in 4 and external carotid artery and vertebral artery in 1). Cranial nerve palsies (cranial nerve VII [n = 1], IX [n = 1], X [n = 4], XI [n = 1], and XII [n = 3]) were the most common cause of surgical morbidity (33% of cases). The patients in the authors’ illustrative cases underwent preoperative embolization and balloon test occlusion followed by resection, and both patients suffered from transient Horner’s syndrome after embolization.
Surgical management of CBTs requires an extensive preoperative workup, anesthesia, and multimodal surgical management. Due to a potentially high rate of surgical morbidity and vascularity, balloon test occlusion with embolization may be necessary in select patients prior to resection. Careful thorough preoperative counseling is vital to preparing families for the intensive management of these children.
Erica F. Bisson, José-Carlos Sauri-Barraza, Toba Niazi, and Meic H. Schmidt
Synovial cysts are uncommon pathological entities in patients with cervical degenerative spinal disease, and there are only a few reports in the literature. Treatment typically involves decompression; however, biomechanical data indicate that laminectomies in the cervical spine also result in cervical instability, specifically within the cervicothoracic junction, supporting the use of fusion as well. The authors describe the use of fusion with decompression in the treatment of 3 patients with cervicothoracic synovial cysts that presented in an acute fashion with associated myelopathy and neurological decline, and they review the diagnostic elements, histopathology, and treatment of these cysts. All 3 of the patients did well with decompression via a posterior approach with a single-level instrumented fusion from C-7 to T-1. Each patient regained complete neurological function and had no residual neurological deficits. These results are promising, although the sample size of 3 cases is too small to make any conclusive evaluations. Future studies incorporating Class I and Class II data are imperative to make firm conclusions regarding general management of this rare entity.
Michael R. Levitt, Toba N. Niazi, Richard A. Hopper, Richard G. Ellenbogen, and Jeffrey G. Ojemann
Chiari malformation Type I (CM-I) is associated with syndromic and nonsyndromic craniosynostosis in pediatric patients, and the surgical management of CM-I in such cases is controversial. Previous guidelines have recommended simultaneous cranial vault expansion and suboccipital decompression. However, spontaneous resolution of CM-I has been observed, and the combined procedure carries additional surgical risks. The authors report the case of a 6-month-old boy with Crouzon syndrome, CM-I, and a cervical syrinx who underwent posterior cranial vault release without suboccipital decompression. Imaging at the 3-month follow-up visit demonstrated complete resolution of the CM-I, improvement in CSF flow, and reduction in the size of the syrinx. This case suggests that up-front suboccipital decompression may not be necessary in patients with craniosynostosis and CM-I. A strategy of initial cranial vault release, followed by watchful waiting and radiographic surveillance, is proposed.
Khaled M. Krisht, Kevin J. Whitehead, Toba Niazi, and William T. Couldwell
Cerebral cavernous malformations (CCMs) are common vascular lesions of the CNS that may lead to seizures, focal neurological deficits, and fatal hemorrhagic stroke. Human genetic studies have identified 3 genes associated with CCM, and biochemical and molecular studies in mice have elucidated signaling pathways with important therapeutic implications. In this review, the authors shed light on the 3 discovered CCM genes as well as their protein products, with particular emphasis on their signal transduction pathways and their interaction with one another. Close focus is directed at mice model studies involving the Ccm2 gene product signaling pathway, revealing an important role for the use of simvastatin or other RhoA inhibitors as a therapeutic modality in the treatment of CCM. The remaining challenges to creating a more faithful CCM animal model as well as future clinical and research implications are reviewed.
Toba N. Niazi, Lubdha M. Shah, Steven S. Chin, and Meic H. Schmidt
Tailgut cysts are developmental cysts that arise from remnants of the embryonic postanal gut and are typically located within the presacral, retrorectal space. Isolated cases of aberrant locations, including prerectal, perirenal, perianal, retrovesical, and subcutaneous locations, have been reported. Malignant transformations with the presence of adenocarcinomas or carcinoids have been recognized within these entities. It is well recognized that anterior sacrococcygeal abnormalities are present and are frequently caused by the slow-growing nature of the tailgut cysts and related mass effect; however, the authors are aware of no reports in the literature of isolated tailgut cysts within the thecal sac in direct contact with neural elements, without extension into the peritoneal cavity. In this case, a 28-year-old woman presented with progressive back pain, frequent urinary tract infections, and bowel dysfunction. She was found to have a purely intradural tailgut cyst with malignant transformation consistent with carcinoid. No peritoneal extension of her disease was found. The authors hypothesize that this is a rare developmental aberration that has not been commonly recognized and potentially has implications for embryological development.
Victor M. Lu, Shelly Wang, David J. Daniels, Robert J. Spinner, Allan D. Levi, and Toba N. Niazi
Malignant peripheral nerve sheath tumors (MPNSTs) are rare tumors found throughout the body, with their clinical course in children still not completely understood. Correspondingly, this study aimed to determine survival outcomes and specific clinical predictors of survival in this population from a large national database.
All patients with MPNSTs aged ≤ 18 years in the US National Cancer Database (NCDB) between 2005 and 2016 were retrospectively reviewed. Data were summarized, and overall survival was modeled using Kaplan-Meier and Cox regression analyses.
A total of 251 pediatric patients with MPNSTs (132 [53%] females and 119 [47%] males) were identified; the mean age at diagnosis was 13.1 years (range 1–18 years). There were 84 (33%) MPNSTs located in the extremities, 127 (51%) were smaller than 1 cm, and 22 (9%) had metastasis at the time of diagnosis. In terms of treatment, surgery was pursued in 187 patients (74%), chemotherapy in 116 patients (46%), and radiation therapy in 129 patients (61%). The 5-year overall survival rate was estimated at 52% (95% CI 45%–59%), with a median survival of 64 months (range 36–136 months). Multivariate regression revealed that older age (HR 1.10, p < 0.01), metastases at the time of diagnosis (HR 2.14, p = 0.01), and undergoing biopsy only (HR 2.98, p < 0.01) significantly and independently predicted a shorter overall survival. Chemotherapy and radiation therapy were not statistically significant.
In this study, the authors found that older patient age, tumor metastases at the time of diagnosis, and undergoing only biopsy significantly and independently predicted poorer outcomes. Only approximately half of patients survived to 5 years. These results have shown a clear survival benefit in pursuing maximal safe resection in pediatric patients with MPNSTs. As such, judicious workup with meticulous resection by an expert team should be considered the standard of care for these tumors in children.
Anna Lo Presti, Alexander G. Weil, Aria Fallah, Eric C. Peterson, Toba N. Niazi, and Sanjiv Bhatia
Sickle cell disease (SCD) is an autosomal recessive hematological disorder, characterized by sickling of the red blood cells in response to a hypoxic stress and vaso-occlusive crises. It is associated with moyamoya-like changes on cerebral angiographic imaging in 43% of patients. Cerebral aneurysms, arteriovenous malformations, and dural arteriovenous fistulas (AVFs) have been described in association with SCD and moyamoya disease. However, the description of a pial AVF (pAVF) in a patient with SCD and/or moyamoya formation has not yet been reported. The authors present the case of a 15-year-old boy with SCD-associated moyamoya disease harboring a pAVF who developed a de novo venous aneurysm 8 months after undergoing indirect superficial temporal artery-middle cerebral artery (MCA) bypass that was complicated by bilateral ischemia of the MCA territory. The pAVF was successfully treated with transarterial embolization using Onyx. The authors describe the possible pathophysiological mechanisms and management strategies for this rare occurrence.